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Learning from Mistakes!. UNRECOGNIZED PROBLEMS & DUBIOUS SOLUTIONS. Acknowledgments. It has been famously said that “ One learns more from mistakes than successes .” Few are willing, however, to call attention to mistakes and failures.
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Learning from Mistakes! UNRECOGNIZED PROBLEMS & DUBIOUS SOLUTIONS
Acknowledgments • It has been famously said that “One learns more from mistakes than successes.” Few are willing, however, to call attention to mistakes and failures. • In the spirit of this learning a series of mistakes (many humorous) from various contributors (mainly anonymous) are presented in this slide show. D.H. Gray Ann Arbor June 2009
Teton Dam Failure “Cavity” Development By 10:00 am the dozer drivers were fleeing for their lives and a cavity had opened gushing muddy water. | v <--dozers Initial “Leak” The initial leak was observed at 8:00 am near the right abutment. Two 20-T dozers were sent down the side of the dam to push dirt into the hole.
Teton Dam Failure “Final Collapse The reservoir behind the dam poured through the gap in the crest… the final washout and collapse of the dam started at 10:58 am. | v “Breach” The dam crest was breached about 10:30 am. Downstream residents were not warned until 10:45 am.
2005 Slope Failure (The 2005 landslide occurred in virtually the same location as the earlier slide. This time 17 homes were destroyed and 10 people, killed. The retaining structure was completely ineffective ) | v La Conchita Landslide 1995 Slope Failure (The 1995 landslide occurred after a prolonged period of rainfall. A number of homes were destroyed, but no one was killed. A massive retaining structure was built to protect against future slope failures.)
Post Hoc Ergo Propter Hoc • Translation: “After it, therefore because of it” Examples: 1. The rooster crowed, and the sun rose, therefore, the rooster made the sun rise. 2. It rained, and the slope failed, therefore, the rain caused the failure Question What caused these slope failures?
Calif College of Engineering Questions Question #1 Would you build your home on this hillside? Question #2 Why or why not?
Iowa College of Engineering Questions Question #1 How much does a house weigh? Question #2 How much weight will a bridge hold?
Iowa College of Engineering Questions Question #3 Whom do you contact in an emergency like this a) Home insurance? b) Auto insurance? c) Road side assistance?
Iowa College of Engineering Questions Question #4 What is the best engineering solution to this problem? Answer:Iowa’s latest covered bridge!
Landuse Zoning?? Aerial Photo 1970 | v <--Trace of San Andreas Fault Aerial Photo 1955
Seismic Hazard Zoning?? Question How can you locate the trace of the Hayward Fault? <--Trace of Hayward Fault Answer By drawing a NW-SE trending line connecting schools and hospitals together!
Coastal Bluff Repair?? <----Failed concrete protective curtain Curtain was blown out as a result of unrelieved pore-water pressure build up in bluff behind curtain Hello…anyone home??
Slope and Streambank Protection?? Lake Michigan shoreline (famous for its scenic beauty) | v Carmel River, California (a favorite stream for rafting)
Slope Holdups and Cover-Ups California “Shrink Wrap” (if you can’t hold it up..at least you can wrap it up) | v California “Plastic Wrap” (the idea is to get the rainwater off your property and on to your neighbor’s as quickly as possible)
Highway Settlement Repair?? Asphalt overlay Slowly settling highway lane was repaired by an annual “maintenance overlays” of asphalt. Increasing weight overloaded the the head of an old landslide and eventually triggered a catastrophic slope failure
Streambank Protection?? US Corps of Engineers Streambank Protection Demonstration Project Big Horn River, Wyoming (a premier fly fishing stream)
Slope Support and Protection?? Texas “Riprap” (new uses for old car bodies) | v Texas “Holdup” (a pickup truck is man’s best friend)
Landslide Warning System Siren---> Devil’s Slide area, coastal Highway 1, California What do you do when the siren goes off…. stop or speed away??
The Poisoning of Michigan Before the 1970s, PBBs were widely used commercially as a flame retardant. In 1973, however, several thousand pounds of PBBs were accidentally mixed with livestock feed that was distributed to farms in West Central Michigan. Some 1.5 million chickens, 30,000 cattle, 5,900 pigs, and 1,470 sheep became contaminated with PBBs and fell ill before the error was discovered. These contaminated animals were slaughtered and scheduled for burial in landfills. All these events were dramatized in the 1981 film “Bitter Harvest” (starring Ron Howard) and in the BBC documentary “The Poisoning of Michigan”
Mio Landfill…the liner the leachatewould never go through The Site Outwash sands with perched ground water table The Plan Encapsulate PBB contaminated cattle carcasses in a compacted, clay envelope
Mio Landfill…cont. The Problem The landfill poorly designed The citizens of Mio not happy The Solution Court allows initial burial in Mio pit… future carcasses transported to desert landfill site in western USA.
Mio Landfill…cont. X-ray radiographs of “healed”cracks Question Can cracks re-hydrate and close? Answer Yes, but cracked zones have much higher hydraulic conductivities Polymeric membrane
RipRap Art - Belle Isle, Detroit A rock revetment provides a handy supply of stone for art projects!
A Culvert (or Bridge) too Far …and a “grand daddy” head-cut in the making!
A Road too Far! Federal highway from Moscow to Yakutsk traverses permafrost that can turn into a linear quagmire in the summer Best time to travel this road is in the winter -------> when the ground freezes solid
WHY WOMEN LIVE LONGER THAN MEN I guess these guys haven’t heard about OSHA regulations yet!
TRENCH CAVE-INS Question What is the maximum “safe” depth of a vertical, unsupported cut (trench) Answer From your foot to the top of your shoulder
